Apparatus for testing the fireresistance of materials



Dec. 18, 1945. E. E. HUBERT 2,391,161

APPARATUS FOR TESTING THE FIRE-RESISTANCE OF MATERIALS 2 Shets-Sheet 1 Filed Sept. 15, 1944;

Dec. 18, 1945. E. E. HUBERT APPARATUS FOR TESTING THE FIRE-RESISTANCE OF MATERIALS F iled Sept. 15, 1944 2 Sheets-Sheet 2 Patented Dec. 18, 1945 g APPARATU'S'FOBI TESIING THE FIRE- RESISTANCE OF MATERIALS Ernest E. Hubert, Seattle, Wash, assignor to" I. F. Laucks, Inc., Seattle, Washga corporation of Washington Application September 15, 1944, serial No. '554,313

' e I 1 Claim. (c1. 7345') This invention relates to apparatus for testing. the fire resistance of. materials, particularly of chemicals. and of treated fabrics. A main. ob-

ject ofthe invention isto rovide a method enabling the. efficacyofdifferent chemicals and of differently treated fabrics to be readily observed and compared. and toprovide relatively simple apparatus for earryingou-t the method. Illustrative apparatus. is shown. in the accompanying drawingswith reference to. which; the invention will be. described. In these drawings I Figure. l is aside elevation of the newappara- Figure 2 is a plan view thereof.

Figure. 3 is a fragmental plan view-omitting an element. which appearsin: Figure 2 I Figure. 4. is a section on line 4-4: of Figure 2. and

. Figure 5 is strip which has been, subjected to a test in accordance with the invention,

.Referring to the drawings, reference. numeral l0. designates. a base to which is secured a socket I tin which isreceived and secured the-lowerv end of an upright round post. I 2. .At its upperend the post has a reduced and threaded portion I3 re.- ceiving a washer [.4 which lies against the sub- J', acent.shoulder.v r r I Reference numeral. t5v designates a plate provided at ,oneqend with an opening receiving the reduced portion l3 'of thepost, the plate being secured against the washer It by means of a nut I 6 so that the plate occupies a fixed angular relation to the post. Plate 15. has a rectilinear edge l6 interrupted by a rectangular opening or recess H which appears more clearly in Figure 3..

Spaced to the left of the recess [-1 and supported by upwardly extending ears I8 and 19 mounted on plate i5 is a spindle 20to which is fixed a knurled eccentric roll 2i, an operating arm Zlhelng fixed to the spindle in radial relation. In Figure 2, F designates a strip of combustiblefabric which-extends under the 11011 2|, across recess H, and beyond the right hand edge of plate 1.5. The fabric is freely disposable under roll 2 I; when the handle is in the full line position of Figures 1 and 2, swinging of the handle counter clockwise causing, thefabric to be firmly clamped between the roll and the underlying plate I5. The fabric is then pulled taught and clamped over the right hand edge of plate l5 by clamping means such as the spring clamp 23. In Figure 1 the free ends of the fabric show outwardly of the clamping means.

Reference numeral 24 designates a rectangular a face view of a portion of a fabric 2'.

plate shown as resting on thefabric strip with an edge registering with the edge It! of plate l5. Adjacent its opposite edge plate 24 has fixed thereto angular hinge brackets 2 5 and having dependingzlegs 21 and 28, Figures. 1 and 4',

which are received freely in notches: as at 29;

v 1 with notches as at 30 inwhich are engaged horizontally aligned pintles carried by blocks 32 and 33' fixed to the under side of plate l5. The described hinging. means permits the plate 24 to lie flatly on the fabric regardless of the thickness of the latter; Inorder thatthe fabric may be readily placed or removed, plate 24 can be swung upwardly and backwardlyto be retained past dead center through engagement; of the legs 21 and 28' with thenotch. end walls as at 34, Figure 4.

Plate 24 has a rectangular edge recess 35 registering with recess H when plate 24 is in its illustrated down position, recess 35 being somewhat Wider than recess. i! so that the top. margins of the latter are exposed as shown in Figure 3.

Reference numeral 36' designates a mask member of thin metal in the form of a shallow channel having a rectangular bottom wall-31, parallel side walls 38 and 39 Figure l, and wings 40 and Al projecting outwardly in the same plane from the upper edges of the side Walls. Anv upstanding end-wall 42' joins. the bottom and side walls and is secured to an arm 43 in turn secured to'a spindle 44 mounted in upwardly projecting ears 45 and 46 on plate 24', the spindle being rockab-le by means of a thumb wheel 45. The mask is of a size to be closely but freely receivable in recess- 35 with its bottom wall 31: resting on the fabric andsupported on the underlying side margins of the recess H with wings 40 and 4 l projecting over the side margins of recess'3-5. Bottom wall 31 is provided'wi-th-substantial-1y trieangular opening 46', Figure 2-, which. is symmetrically disposed with its base adjacent and parallel tothe end wall" 42, the. apex of the opening being, slightly truncated or blunted as here shown.

In testing the fire proofing capacity of a chemical, in accordance with the invention, a strip. of fabric is clamped in place, as heretofore described, and plate 24 and mask member 36 are swung intoengagement with the upper surface of the fabric so that an area of the latter is fr med in the recesses l1 and 35. The chemical, ordinarily in finely powdered form, is appliedor deposited on the fabric exposed by the opening 46' andcarefull tamped and leveled off. The mask is then swung to the dotted line position of Figure 1 so that a triangular pattern of the chemical, smaller than the framed area of the fabric left and of the thickness of wall 31, is left on the fabric. The fabric is now ignited at its edge at the point P which is on the bisector of the opening 46. The flame and glow are allowed to creep in toward the apex of the triangle and beyond so that the fabric area beneath the pattern is subjected to the burning effect, Preferably the glow along the sides of the path of travel 9; theflame is extinguished in order to keep thepattern even.

The action of the chemical in preventing flame and glow from destroying thefabric beneathitis now observed. The completedestruction of the fabric in the frame area indicates least resistance. If, as in Figure 5, thereremains an,intact and uncharred tongue 41 of the same size as the original pattern, highest resistance is indi-. cated. W Intermediate conditions of cloth and shapes of pattern give indications of fire resist ance between the two extremes' The pointed pattern gives a useful result in showing whether the chemical under test causes the flame to part and proceed down each side of the apex or whether it continues on through without partingJ The rapid selection of the most promising chemical out of along list of possibleflre retardants is thus made possible. Tests quickly show, for example, that borax leaves a triangular tongue of unburned cloth beneath it; that zinc oxide permits flame and glow to travel beneath it, charring and destroying the fabric; and that calcium metaborate prevents flame but permits glow to travel beneath, charring and destroying the fabric. l

After testing, the test strips of fabric are pasted on cardboard sheets and Labeled. This provides a ready reference to tests made on any chemical or group of chemicals, and a recordsheet furnishesthe recorded data; The tests quickly determine whether a chemical intumesces upon contactwith the flame, melts into' the fabriqdecomposesproduces flamefresisting gas or gases, decomposes oralters the fabric, loses water, com bines two or more of thesecharacteristic's, or is b i'., e r 1. V.

For testing of the fire resistant character of treated fabrics, the lowing struct'1 ire: V, Beferring'to Figures 1 and 2, reference numeral- 48 designates a plate welded to a collar 45 and supported on socket H for swinging on the axis of post l2. Reference numeral 50 designates a gaspipe supported under plate 48 by means of aihanger 5| and running to a vertical burner tube 52 which extends through'an openingi'in' plate -48, beingfixed in a mounting ring 53 which is screwed to the bottom of the plate. Mounted'on plate 48 concentrically with the burner'top 52i's'a cylindrical chimney 54 which extends upwardly almost to the height of the lower surface of plate I5, the chimney having a door provided with nob 55' so 'as to give" access to.

the burner. 'Collar 49 is equipped at its upper end with stop means cooperable with stop means on acollar 56 fixed on a post I2 so that'the plate 48 andappurtenancesare swingable between the apparatus'includes the foli V dotted line position and the full line position (where exposed), Figure 2, and in the latter position the burner 52 is centered beneath the apex of the opening 46', i. e., substantially centrally of the framed area of a fabric strip which is to be tested. Plate 48 occupies the dotted line position when tests such as first described are to be made V r The fabricto be testedfor flame and glow resistance is ordinarily a light weight fabric such as poplin, twill, etc., used, for example, in flying suits or for other purposes where light weight fabrics are necessary. Standard tests as used to test the resistance of canvas and duck fabrics are too severe for the light weight fabrics for which the present test has been principally devised. In making thejtests, the mask 36 is moved out of the way to the dotted line position of Figure 1. The burner, occupying the dotted line position of Figure 2, is lighted and the flame length is adjusted sq thatwhen theburner is moved under the fabric thepoint of the flame (500515. :10) will justtouchthe lower surface of the framed area, andthe air vent at the base is entirely closed off. The burner is now swung under the exposed fabric, left, for example, for five seconds, and fllQI ll SWullg away. The periodof flaming and glowing are observed after removal of the flame. Untreated cloth ignites and burns out completeilypdeaving ,a rectangular opening in the test piece. I n the ease of a treated fabric the pattern and extent of the charring are important indications of fire resistant character in cases where no flame or glow remains after, removal of the test flame. I

This method of testing has been found useful in determining the difference in the fire resistance of leached and unleached halves of standardtwoinch by twelve inch fabric test strips. These strips after' treatment throughout with the fire retardant solutiona're suspendedin a leaching tank with the lower half only of the strip, in the Water and leached, "for example, for twentyrcsurhdursatthe rate of seventeen gallons per hour. "After drying and conditioning, the halves of each strip are successively clamped in the testingapparatus'and exposed to the test flame.

It will be evidentthat the described procedures and apparatus are susceptible of variations. Consequently, I do not limit myself to the specific disclosure herein, except in the following claimf "'I'iclai'm: Apparat'us for subjecting fabricsto a fire test, comprising a horizontal plate having a rectilinear edge and a recess terminating at said edge, means associated withfs'aidjxlate and spaced'from the sidesof said recess for clamping a strip of fabric on said plate and across said opening, a second plate adapted to rest on'the clamped fabric be tweensaidclamping means and'having an edge recess registering with the first mentioned recess, 

